This activity and demonstration teaches the concept of parallax (the apparent movement of an object caused by a change in the viewer's position) and relates the concept to a real-world astronomical event, ­the discovery of Pluto. It employs the Blink Comparator, an online simulation illustrating the technique used by Clyde Tombaugh to discover the ninth planet on February 18, 1930.
Full description.

This three-part module covers the major concepts of the chemistry of water, at a level appropriate for late primary and early intermediate learners. Key vocabulary words are defined using examples that are relevant to children's lives. Each part of the module contains an activity or experiment to reinforce the science content that was covered.
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Where
oceans
and
seas
meet
land,
the
change
is
abrupt
and
sudden.
The
plants
and
animals
that
call
this
transition
zone
home
have
interesting
adaptations.
Users
can
view
pictures
and
read
about
several
types
of
shorelines
and
coastal
features
(sandy
shores,
barrier
islands,
rocky
shores,
tide
pools,
estuaries,
salt
marshes,
mud
flats,
and
mangrove
forests),
the
plants
and
animals
that
inhabit
them,
...
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This is an online activity book from the National Weather Service that teaches about hazardous weather. The site also includes links to kids sites for the Federal Emergency Management Agency (FEMA) and the National Oceanic and Atmospheric Agency (NOAA).
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Each
student
will
keep
a
science
journal
during
each
of
the
four
seasons.
Students
will
record
observations
of
the
general
outdoor
environment
they
visit
and
then
will
make
observations
of
one
specific
item
from
the
habitat
in
each
season.
At
the
end
of
the
school
year,
students
will
make
comparisons
of
their
seasonal
drawings
and
share
the
results
with
the
class.
The
purpose
of
the
activity
is
to
...
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In
this
activity
students
construct
a
sundial
and
use
it
to
observe
the
movement
of
the
sun
through
the
sky
over
the
course
of
a
day
by
marking
changes
in
the
position
of
a
shadow
once
each
hour.
Students
determine
the
approximate
time
of
solar
noon
at
their
school
as
indicated
by
the
time
of
the
shortest
shadow.
They
revisit
the
site
on
a
subsequent
day
to
estimate
the
time
of
day
using
their
sundial.
...
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In
this
activity
students
observe
and
sketch
clouds,
describing
their
forms.
They
initially
generate
descriptions
of
a
personal
nature
and
then
move
toward
building
a
more
scientific
vocabulary.
They
then
correlate
their
descriptions
with
the
standard
classifications
using
the
ten
cloud
types
identified
for
GLOBE.
Each
student
develops
a
personal
cloud
booklet
to
be
used
in
conjunction
with
the
GLOBE
...
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The
purpose
of
this
activity
is
to
observe
the
type
and
cover
of
clouds
including
contrails.
Students
observe
which
of
ten
types
of
clouds
and
how
many
of
three
types
of
contrails
are
visible
and
how
much
of
the
sky
is
covered
by
clouds
(other
than
contrails)
and
how
much
is
covered
by
contrails.
Intended
outcomes
are
that
students
learn
how
to
make
estimates
from
observations
and
how
to
categorize
...
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The
purpose
of
this
activity
is
to
explore
the
connections
between
cloud
type,
cloud
cover,
and
weather
and
stimulate
student
interest
in
taking
cloud
type
observations.
Students
observe
cloud
type
and
coverage
and
weather
conditions
over
a
five-day
period
and
correlate
these
observations.
Students
make
and
test
predictions
using
these
observations.
The
intended
outcome
is
that
students
learn
to
draw
...
Full description.

The
purpose
of
this
resource
is
to
have
students
develop
a
qualitative
understanding
of
the
characteristics
and
patterns
of
seasons
and
highlight
the
relationship
of
seasons
to
physical,
biological
and
cultural
markers.
Students
observe
and
record
seasonal
changes
in
their
local
study
site.
They
establish
that
these
phenomena
follow
annual
cycles
and
conclude
the
activity
by
creating
displays
that
...
Full description.